Conductive flexible coupling

ABSTRACT

A conductive flexible coupling for coupling together two rotatable shafts in which a flexible member disposed between and connected to a conductive flange carried by one shaft and to a conductive flange carried by the other shaft is provided on at least one side thereof with a flexible screen for providing an electrical path between the two conductive flanges.

United States Patent LaFramboise [54] CONDUCTIVE FLEXIBLE COUPLING [72] Inventor: Leo F. LaFramboise, Saginaw,

Mich.

[73] Assignee: General Motors Corporation,

Detroit, Mich.

[221 Filed: Nov. 9, 1970 [21] Appl. No.: 87,773

[52] US. Cl ..339/3, 64/ 1 3 [51] Int. Cl. ..H0lr 5/06 [58] Field of Search ..9l/380; 64/10, 13; 180/78; 339/3, 96, 7

[56] References Cited UNITED STATES PATENTS 1,376,107 4/1921 MacDonald ..64/l3 [151 3,684,999 51 Aug. 15, 1972 1,067,024 7/1913 Hall et a1. ..339/96 X 2,753,848 7/1956 Burton ..9l/380 3,115,759 12/1963 Crane ..64/10 X 3,360,963 1/1968 Turunen ..64/1 3 3,386,069 5/1968 Eriksson ..339/7 Primary Examiner-Richard E. Moore Attorney-Jean L. Carpenter and Arthur N. Krein [57] ABSTRACT A conductive flexible coupling for coupling together two rotatable shafts in which a flexible member disposed between and connected to a conductive flange carried by one shaft and to a conductive flange carried by the other shaft is provided on at least one side thereof with a flexible screen for providing an electrical path between the two conductive flanges.

3 Claims, 4 Drawing Figures PHENTETIAIJ: 15 m2 3.6 84,999

INVENTOR.

ATTORNEY CONDUCTIVE FLEXIBLE COUPLING This invention relates to steering apparatus for use in automotive vehicles and the like and, in particular, to a bipartite steering shaft in which the two shaft sections are interconnected by a conductive flexible coupling to provide a continuous electrically conductive path through the steering shaft arrangement for an electrical operated horn or the like.

Flexible couplings of thetype, for example, as disclosed in. U.S. Pat. No. 2,753,848 issued on July l0, 1956, to Robert W. Burton, have been used fora number of years to couple together the shaft sections of a steering shaft of an automotive vehicle. In this type of coupling, the flexible element is normally made of rubber, canvas and rubber discs bonded together, or other similar materials which are electrically nonconductive. With the use of such a prior art coupling in the steering shaft column, there is a break at-the coupling in the conductive electrical 'path through the steering. shaft column and, accordingly, when elements, such as a horn button, were provided in the steering column, an additional electrical conductive circuit in the form of a wire had to be employed to effect grounding of the horn relay when the horn button was depressed.

It is therefore the primary object of this invention to provide a flexible coupling for use on a bipartite steering shaft whereby a conductive screen is provided on the flexible member of the flexible coupling for providing an electrical path between the two shaft elements being coupled together.

Another object of this invention is to improve a flexible disc for use in a flexible coupling whereby one surface of the flexible disc is'provided with a flexible conductive wire grid adapted to provide electrical contact between mating parts of the flexible coupling.

These and other objects of the invention are attained by means of a conductive flexible coupling comprising a flexible member having a conductive screen bonded on one side thereof with the wires of the screen exposed at the surface of the flexible element, the flexible member being disposed between the flange carried by an upper steering shaft section and the flange carried by a lower steering shaft section, the lower :flange section being connected to the flexible member with the rivet connectors extending axially for engagement .in slotted portions of the flange element on the upper steering shaft member and, a pair of connectors in :the form of bolts are used to secure the flange of the upper shaft section to the flexible member.

For a better understanding of the invention, as well as other objects and further features'thereof, reference is had to the following detailed description ofithe invention to be read in connection with the accompanying drawings, wherein:

FIG. 1 is a longitudinal sectional view of the conductive flexible coupling of the invention used to connect the lower and upper shaft sections of a steering column together;

FIG. 2 is a sectional view taken at right angles to the sectional view of FIG. 1;

FIG. 3 is a view taken along line 3-3 of FIG. 1; and,

FIG. 4 is a view taken along line 4-4 of FIG. 1.

Referring now to FIGS. 1 and 2, the upper steering shaft section of the steering column of an automotive vehicle is coupled to the lower shaft section 12 by a flexible coupling, generally designated 14, constructed in accordance with the invention. The flexible coupling 14 includesa pair of flanges l6 and 18 with a flexible disc '20 therebetween.

The upper steering shaft section 10 which is enclosed by a steering column or mast jacket22 and held against .end of the steering column 22. A sealing ring 28 is interposed between the flange l6 and the bearing support ring 26.

The lower shaft section 12 is spline connected at its .upper end to the split hub portion 32 on-the lower flange '18, the split hub portion 32 being clamped securely to the shaft section12 by means of bolt 34.

Flexible coupling 20, in accordance with the invention, includes a main flexible body portion 36 faced at one end thereof with an exposed flexible conductive wire grid 38. Body portion 36 made of rubber or similar material can be made as a single disc or, as shown, as a stack of rubberized or elastomerized. fabric or paper discs suitably bonded together. The flexible conductive wire grid 38 is conveniently in the form of a metal wire screen, as for example, a l2 X 12 mesh to 24 X 24 mesh steel wire screen with the wire screen set in the material of the body portion 36 but with the metal exposed on the outer surface-of the .composite flexible disc.2 0.

The :upper flange :16 is substantially circular in configuration while lower flange 18 is generally bar-like in form, as seen in FIG-4. Upper flange 16 is secured by suitable connectors, as by a pair of bolts 40 and nuts 42, directly to the flexibledisc 20 with a semi-circular reinforcement strap 44 positioned on'the opposite side of the flexible disc .20 from the upper flange 16, whereby through these bolt and nut connectors, the uppersflange 16 is held in .direct electrical contact with the wire grid "38 in the two areas as seenin FIG. 2.

nectors, in the form of rivets 46, to the flexible disc 20.- As shown in FIG. .1, each rivet-46 has a stepped shank portion 48 extending through a reinforcement plate-54, the flexible disc 20 and the lower flange 18 with the portion of the stepped shank portion 48 of largest diameter being substantially coextensive with the thickness .of the flexible disc 20. In addition, each rivet 46 is provided with an extension 50 received in a slot :52 formed in the upper flange 16. Thus, each rivet 46 fixed to the flange 18 is also in electrical contact with the wire grid 38 through the contact of its shoulder against the reinforcement-plate 54.

The-reinforcement strap '44 and reinforcement plate 54 are usedto distribute the pressure of the connectors, bolts 40 and rivets 46, over substantial areas on the faces of the flexible disc 20. Reinforcement plate 54 is made of metal or other conductive material to provide theelectrical contact between the wire grid 38 and the rivets '46.

With this arrangement, it is obvious that although the bolts 40 serve only to secure the upper flange 16 to the flexible disc 20, the rivets 46 in addition to securing the lower flange 18 to the flexible disc 20 also provide,

together a first shaft and a second shaft comprising a first flange adapted to be secured to said first shaft, a second flange adapted to be secured to said second shaft, a flexible disc, first connector means connecting said flexible disc to said first flange, and second connector means connecting said flexible disc to said second flange, said second connector means being positioned to be in driving connection with said first flange, said flexible disc including a main flexible body portion and a flexible wire grid screen of conductive material set in said body portion with said wire grid screen exposed on one side for electrically connecting said first flange and said second flange, through said first connector means and said second connector means, together. i

2. In a steering apparatus including a steering shaft having an upper shaft section and a lower shaft section joined together by a flexible coupling, said coupling comprising a first flange secured to said upper shaft section, a second flange secured to said lower shaft section, a flexible disc having a conductive wire grid screen secured thereon, first connector means connecting said flexible disc to said first flange with said wire grid screen in electrical contact therewith, and second connector means connecting said flexible disc to said second flange with said second connector means in electrical contact with said wire grid screen, said second connector being positioned to be in driving connection with said first flange.

3. In a steering apparatus including a steering section having an upper shaft section and a lower shaft section joined together by a flexible coupling, said flexible coupling comprising a first flange secured to said upper shaft section, a second flange secured to said lower shaft section, a flexible member disposed between said first flange and said second flange, a first pair of connectors connecting said flexible member to said first flange, a second pair of connectors connecting said flexible member to said second flange, said second pair of connectors extending into driving engagement with said first flange, said flexible member including a flexible body portion with a flexible wire grid screen of conductive material secured at least on one surface thereof and positioned in electrical contact with said first flange and being connected electrically through said 

1. A conductive flexible coupling for connecting together a first shaft and a second shaft comprising a first flange adapted to be secured to said first shaft, a second flange adapted to be secured to said second shaft, a flexible disc, first connector means connecting said flexible disc to said first flange, and second connector means connecting said flexible disc to said second flange, said second connector means being positioned to be in driving connection with said first flange, said flexible disc including a main flexible body portion and a flexible wire grid screen of conductive material set in said body portion with said wire grid screen exposed on one side for electrically connecting said first flange and said second flange, through said first connector means and said second connector means, together.
 2. In a steering apparatus including a steering shaft having an upper shaft section and a lower shaft section joined together by a flexible coupling, said coupling comprising a first flange secured to said upper shaft section, a second flange secured to said lower shaft section, a flexible disc having a conductive wire grid screen secured thereon, first connector means connecting said flexible disc to said first flange with said wire grid screen in electrical contact therewith, and second connector means connecting said flexible disc to said second flange with said second connector means in electrical contact with said wire grid screen, said second connector being positioned to be in driving connection with said first flange.
 3. In a steering apparatus including a steering section having an upper shaft section and a lower shaft section joined together by a flexible coupling, said flexible coupling comprising a first flange secured to said upper shaft section, a second flange secured to said lower shaft section, a flexible member disposed between said first flange and said second flange, a first pair of connectors connecting said flexible member to said first flange, a second pair of connectors connecting said flexible member to said second flange, said second pair of connectors extending into driving engagement with said first flange, said flexible member including a flexible body portion with a flexible wire grid screen of conductive material secured at least on one surface thereof and positioned in electrical contact with said first flange and being connected electrically through said second pair of connectors to said second flange. 